Electric switch construction



Aug- 15, 1950 G. L. THIRY 2,519,205

ELECTRIC SWITCH CONSTRUCTION Filed June 2s, 1947 3 Sheets-Sheet l i 'H10 .......n

INVENTOR. GEO/e654; ivf/,ey

Aug. l5, 1950 G. L. THIRY ELECTRIC SWITCH CONSTRUCTION Filed June 28, 1947 3 Sheets-Sheet4 2 INVENTOR G50/622. 21H/,6P

I. A" I' l" l; y :5% L I 4 w www i Aug. l5, 1950 G. L. THIR:

ELECTRIC SWITCH CONSTRUCTIN 3 She'ts-Sheet 5 Filed June 28, 1947 Patented Aug. 15, 1.9550

GeorgeLean Thiry, "Milwaukee, assis-.nor to McGraw Electric fGompanx, a .prncratignf IDelaware Applieation Jlme, 1947,.Seria1No.757,8`05

x2 Claims.

"This invention relates to electric switch construction and 'is particularly "directed to Aall switches either of the multiple or single type.

In switches of this type it has' been the practice to provide 4stationary contact blocks v and a movable contact member of a variety of designs to engage thesaid vstationary contact blocks. Other designs have embodied a laminated or brush type Astationaljy `Contact Ablok engaged by a solid movable contact member.

An object of this invention is to Iprovide a switch Ain whichk a relatively rigid movable contact member is normally maintained in Contact relation to a y.pair of .rigid stationary contacts by resilient means comprising Jin :part .operating mechanism for the movable Contact.

More specifically, an objectof this invention zis to provide an eletica-l switch mechanism in which each otapair ofstationarycontact blocks includes a Vsshaped contact receiyingportion, a tubular .Contact l.member lmovable into the Veshaoed portions. 'and resilient meansfcr maintaining engagement-.between said ,member land portions.

Another object is to: providea switch operating ,mechanism .including means compensating for dimensional nequalites lwhich .are .the fre- Sult 0f the yuse 10.1 .insulating supporting imam.- beis fand .thereby'lfacilitating .the assembly :and operation of a movable contact relative tostatonaly contacts..

vAndtlner object .is to-.provide aswih mecha.-

nism in which theniovable lContact ybar is self adjusting so .that 'itzamgay rock freely fto. properly engage the fixed Vcontacts to .insure -afperfect Contact.

Still another .obj ect-sis fto Y provide 4a .replaceable contact follower for maintaining a .delayedelectrical yconnection between 4 the i stationary and movable :Contact :members .-.to minimize spitting the movablecontact memberrwhen separated from the stationary .members or .when brought :into Contact therewith, suchffollower being freelyand automatically adjustable toiopen thecircuitafter separation.ofthecontact members or to close circuit before Contact members are engaged irrespective of Wear ofthe parts.

l Further `objects and advantages of the invention will be apparent from the riollowing-description and from the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

JFig. l is a view with'the end Vof the .switch housing as viewed irom'theleftrelative toigg cut .away to show the switch .in closed position.

Fig. 2 lis an. enlarged view of rtheoperatingand latching mechanism shown in Fig. 1 as it appears when the switchiis closed.

Fig. 3 is a view similar switch in openposition.

Fia f1 is .an ,enlarsedriew 4oi-.tue operating to Fig. l showingzthe Jil lwith as viewed from the -3 for containing an insulating Aarev Y on the operating mechanism.

Fig.v 'Tis a view `partly broken away taken on the'lineT-J of Fig. 6.

rFigxS is afragmentary view showing a stationary contact and Aswitch blade engaged there- `right relative to Figfl. The `switch 'illustrated in the id rawings is designed for operation `in a three vphase circuitybut since each of the phases is controlled by switch meehanismsimilar to `that controlling the other phasesyl deemed -it suicient to show only one such switch mechanism.

`The-switch hereafterdescribed is enclosed-in a-housing comprising abody portion I `for mounting theswitch mechanism, a cover 12, and tank quenchingy o il surrounding-the switch-contacts. The cover-eis removably clamped to the l l body -l able means such as bolts 2a, andf-'the-tankissupportedfromthe -body -by swiveled suspension rods The vinner `walls vand A'bottom of thewtank 3 are lined with'insulating panelsljS-b. ySuitable sealing gaskets will, of course,-be-provided between the several adjacent-parts of the housing.

-A switch supporting a.base-plate -4 -is mounted inthe body portion-i abovetheftank. Spaced insulating bushings -5 surrounding vconducting rods 5 -are-.mountedon-the fbase Apla-te yi and extend-'trom the linterior -of thev'lbody portion `l `vto the interior -of vthe tank A.3. `z-Nuts'fl on each of the 4rods 6 secure a line terminal-8-totherod- VVAline wire-9a (not shown .inFigs l andS,l -butshown-in Fig. e) extends `irom each-o1 the .terminals to the'exterior of thefhousing through -bushings'f mounted'on thebody -l.

insulating caps .32 cover-the upper ends of the bushings 5 therefrom.

.The Alower .end oileachconducting trod. 6 is provided.withastationarycontact block AHlfwhich is held in clamped engagement with .the lower end .of `the rcorresponding :bushing l5 by. .means of the .lower one of the-nuts :Each block-is .provided witha contactsuizface sin the form .oan inverted V shape Vgroove :38 transversely Iof Figs. l ,and 3 to .serve l.as -a.-contaet seat .for the-cylindrical switehblade lil (see iEigpS). Preferably, each blockY IB ispprovided with .aresilientfauxiliary arcing contactgl comprising. a wir.e.bent in substantially rectangular Yform :with .each end .and 9 'and the slive -parts Yprojecting gbent toward the other .and .socketed .in :a :recess ononeside of theblock .loiset from the-recess in which the other .endcisesocketed .on .the opposite side vof the eblock t0. rThis Y.arrangement places .the auxiliarypontact .fl 2 .under stress .tendaing/.tourge the freelymovable;sidenownwardly n rod'25 against the blade II. Pins 12a limit the extent of the downward movement of the free side of the auxiliary contact I2. As indicated, the freely movable side of each auxiliary contact l2 is disposed laterally of the contact block II) which supports it. This insures that the arcing occuring on opening or closing of the circuits will occur at points spaced from the areas of contact between the blocks Ill and blade Ii.

The blade Il is mounted on the lower end of the insulating rod 25 by means of a pair of op posed angle straps I4 each of which is apertured at 2,5 to loosely embrace the blade il. vSpaced cotter pins I3 extend transversely through the blade l I and allow limited shifting movement of the blade II on the angle straps I4 but permit the blade II to rock in the apertures 26 sumciently to allow proper alignment with the V- slots 38 in the contact blocks I0.

The insulating rod 25 extends upwardly through the aperture 27 in the base plate il and into the space dened by the body I and cover 2 ofthe housing. Mounted on upper end of the is an inverted U-strap 28 having an aperture 3! in its base. Extending horizontally between -the legs of the strap 28 is a crosshead bar I8 having threaded post 3i! projecting upwardly through the aperture 3| in the base of the strap 28 and supported by nut 35 secured against rotation by lock nut 3l. A coil spring 35 surrounding the posil S, urges the bar I8 downwardly.

The left end of the crosshead bar i3 as viewed in Fig. is apertured at 2i to receive a guide post 22 and the side opposite the threaded post 35 is provided with a depending tongue 29 to which a pair of links II is connected. A second guide post (not shown) is provided for the opposite end of the bar I8.

The operating mechanism includes a handle 23 exteriorly of the housing rsecured to a rocker shaft I5 projecting into and journaled in the walls of the body I. Secured to the shaft interiorly of the body I is a lever I5 pivotally connected at its free end with the lower ends of links I'. The free end of the lever l5 is prof vided with a lprojecting stop member i9 engageabler with stop pin 2 connecting the links i1 intermediate the pivotal connection of the links I1 with tongue 29 on the bar I8 and the pivotal connection of the links Il with the lever IS. The stopmember iS and pin 20 are so arranged that the pivotal connectionbetween the links Ii and the lever I6, as viewed in Fig. 1 is disposed slightly to the right of a plane common to the axis of the shaft between the links I7 and tongue 2S on the bar I8, thus preventing collapse of the connection between the shaft l5 and the bar I8 when the switch blade II is in the closed position as illustrated in Figs. 1 and 5.

When the switch blade I I is moved to the open position shown in Fig. 3, the handle 23 which will normally extend horizontally to the left will be rotated counter-clockwise until the lever I5 rests on the stop lug 24 on the base 4. Movement of l the lever I5 in the manner indicated carries the lower ends of links I7 downwardly to the left of the insulating rod 25 and permits the switch blade Il and its supporting structure to descend to the position illustrated in Fig. 3.

As the switch blade II leaves the contact blocks I0, the auxiliary contacts I2 will maintain an electrica1 connection between the blade II I5 and the pivotal connection and contacts le until the auxiliary contacts rest onthe stop pins lZa.V Thismode of operation between the blade Il,` auxiliary contacts I2 and blocks it insures that arcing will occur only between the blade l l and auxiliary contacts I2 and at points on the blade Ii spaced from points of contact thereof with the contact blocks I.

As clearly illustrated in Fig. 2, the crosshead bar i8 is maintained in a position which carries the post 36 upward to a point where the nut 35 is spaced from the base of the U-strap 28. This lpermits the bar I8 to maintain the movable switch blade II in resilient contact with the spaced stationary contact blocks IG through the action of the coil spring 35 on the U-strap 28.

I have stated that the disclosed switch is de signed for a three phase circuit. It is believed that it will, without duplicating the View of the switch shown in Fig. 5, be obvious that each phase of the circuit will have a similar arrangement, each phase switch being operated simultaneously with the others through the shaft i5 common to each switch.

It will appear from the foregoing, that a novel switch operating mechanism is disclosed, that such mechanism embodies a combination of elements which aord the use of simple, solid contacts in abutting relation and that simple effective means are provided for avoiding arcing between the contacts.

l claim:

1. In a switch, comprising a pair of spaced stationary contact blocks, each having a V- groove in substantial alignment with the other, and a cylindrical switch blade normally seated in said grooves in bridging relation to said blocks and movable therefrom; and an auxiliary arcing contact carried by each of said blocks and comprising a resilient wire loosely embracing said block with each of its ends journaled in a side of said block on an axis oiset from the axis of the other, the journaled mounting of the arcing contact producing a stress in said wire biasing the freely movable side of said wire into contact with said switch blade. Y

2. n a switch, comprising a pair of spaced stationary contact blocks, each having a contact surface in substantial alignment with the other and a switch blade normally seated on said contact surfaces in bridging relation to said blocks and movable therefrom; an auxiliary arcing contact carried by each of said blocks and comprising a resilient wire loosely'embracing said block with each of its ends journaled in a side of said block opposite that of the other on an axis oifset from the axis of the other, the journaled mounting of the arcing contact producing a stress in said wire biasing the freely movable side of said wire into contact with said switch blade.

GEORGE LEON THIRY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,158,492 Harris Nov. 2, 1915 1,206,552 Leece Nov. 28, 1916 1,552,271 Burnham Sept. l, 1925 1,635,544 Crichton July l2, 1927 1,774,456 Salisbury Aug. 26, 1930 FOREGN PATENTS Number Country Date 15,136 Great Britain 1997 343,907 -Great BritainY Feb. 25, 1931 

